Tools Required
J 38792-A Electronic
Vibration Analyzer (EVA) 2
Notice: Do not fill the propeller shaft with foam, oil, or any other substance
in order to correct a vibration. Filling the propeller shaft is only effective
in reducing an unrelated condition called Torsional Rattle. Filling the propeller
shaft should only be done in strict adherence to the procedure outlined in
corporate bulletins that address Torsional Rattle. Failure to follow the correct
procedure will induce a vibration and/or affect the structural integrity of
the propeller shaft. The propeller shaft will then have to be replaced.
- Support the vehicle on a hoist or jackstands. Support the drive
axle, or axles at curb height. Refer to
Lifting and Jacking the Vehicle
in General Information.
- Turn the ignition ON.
- Place the transmission in NEUTRAL.
- Remove the rear tire/wheel assemblies. Refer to
Tire and Wheel Removal and Installation
in Tires and Wheels.
- Remove the brake rotors from the drive axle, or axles. Refer to
Front Brake Rotor Replacement
and/or
Rear Brake Rotor Replacement
in Disc Brakes.
- Hold the vibration sensor of the J 38792-A
Electronic Vibration Analyzer (EVA) 2, against the
pinion nose.
Notice: Do not depress the brake pedal with the brake rotors and/or the brake
drums removed, or with the brake calipers repositioned away from the brake
rotors, or damage to the brake system may result.
- Start the vehicle.
- Place the transmission in the highest forward gear.
- Have an assistant accelerate and decelerate the vehicle through
the speed range at which the vibration was first noted during the Vibration
Analysis - Road Testing procedure.
- If a vibration is present, note the J 38792-A
reading during acceleration or deceleration.
- Note as to whether or not the pinion nose vibrates under load
during the acceleration or deceleration.
- If the vibration is not reproduced, reinstall the brake rotors
and the wheel/tire assemblies to put an additional load on the system. Check
the components again while an assistant maintains the vehicle at the vibration
concern speed.
- If the vibration is still not reproduced, lightly apply the brakes
to further load the system while maintaining the vibration concern speed.
- If the pinion nose vibrates under acceleration or deceleration,
and other driveline components have been eliminated as a cause, the vibration
may be an internal axle problem.